Graphene - Page 2

Researchers use new experimental method to probe spin structure in 2D materials for first time

Researchers from Brown University, Michigan State University, Columbia University, Sandia National Laboratories in the U.S, Japan's National Institute for Materials Science and Austria's University of Innsbruck have observed low-energy collective excitations in twisted bilayer graphene near the magic angle, using a resistively detected electron spin resonance technique. 

For many years, scientists have been trying to directly manipulate the spin of electrons in 2D materials like graphene. Doing so could yield key advances in the world of 2D electronics, a field where super-fast, small and flexible electronic devices carry out computations based on quantum mechanics. Standing in the way is that the typical way in which scientists measure the spin of electrons — an essential behavior that gives everything in the physical universe its structure — usually doesn’t work in 2D materials. This makes it incredibly difficult to fully understand the materials and propel forward technological advances based on them. But a team of scientists led by Brown University researchers believe they now have a way around this longstanding challenge. 

Read the full story Posted: May 12,2023

Researchers design room-temperature spin-valve with vdW Ferromagnet Fe5GeTe2/graphene heterostructure

The discovery of new quantum materials with magnetic properties could pave the way for ultra-fast and considerably more energy-efficient computers and mobile devices. So far, however, these types of materials have been shown to work only at extremely cold temperatures. Now, for the first time, a research team at Chalmers University of Technology, Lund University and Uppsala University in Sweden has created a two-dimensional (2D) magnetic quantum material that works at room temperature.

Today’s rapid expansion of information technology (IT) is generating massive amounts of digital data that needs to be stored, processed and communicated. This requires energy, and IT is projected to account for over 30% of the world’s total energy consumption by 2050. To solve this problem, the research community is entering a new paradigm in materials science. The research and development of 2D quantum materials is opening new doors for sustainable, faster and more energy-efficient data storage and processing in computers and mobiles.

Read the full story Posted: Apr 24,2023

Researchers examine the prospects of 2D materials for non-volatile spintronic memories

A new study, coordinated by ICN2 group leaders and ICREA professors Prof. Stephan Roche and Prof. Sergio O. Valenzuela, and by Prof. Hyunsoo Yang from the National University of Singapore, examined the current developments and challenges in regards to MRAM, and outlined the opportunities that can arise by incorporating two-dimensional material technologies. It highlighted the fundamental properties of atomically smooth interfaces, the reduced material intermixing, the crystal symmetries and the proximity effects as the key drivers for possible disruptive improvements for MRAM at advanced technology nodes.

The research was carried out by a collaboration of various members of the Graphene Flagship project consortium, including various institutes of the Centre national de la recherche scientifique (CNRS, France), Imec (Belgium), Thales Research and Technology (France), and the French Atomic Energy Commission (CEA), as well as key industries such as Samsung Electronics (South Korea) and Global Foundries (Singapore).

Read the full story Posted: Jun 28,2022

Researchers find that graphene-on-chromia heterostructures show potential for spintronic devices

University of Nebraska-Lincoln's scientist Christian Binek and University at Buffalo's Jonathan Bird and Keke He have teamed up to develop the first magneto-electric transistor.

Along with curbing the energy consumption of any microelectronics that incorporate it, the team's design could reduce the number of transistors needed to store certain data by as much as 75%, said Nebraska physicist Peter Dowben, leading to smaller devices. It could also lend those microelectronics steel-trap memory that remembers exactly where its users leave off, even after being shut down or abruptly losing power.

Read the full story Posted: Apr 22,2022

Researchers make strides in graphene spintronics

Researchers at The University of Manchester and Japan's National Institute for Materials Science seem to have made a significant step towards quantum computing, demonstrating step-change improvements in the spin transport characteristics of nanoscale graphene-based electronic devices.

Tunable Spin Injection in High-Quality Graphene image

The team used monolayer graphene encapsulated by another 2D material (hexagonal boron nitride) in a so-called van der Waals heterostructure with one-dimensional contacts. This architecture was reported to deliver an extremely high-quality graphene channel, reducing the interference or electronic ‘doping’ by traditional 2D tunnel contacts.

Read the full story Posted: Feb 11,2022

Spin-orbit–driven ferromagnetism detected in 'magic-angle' twisted bilayer graphene

A research team from Brown University has found a surprising new phenomenon that can arise in 'magic-angle graphene' - two sheets of graphene that are stacked together at a particular angle with respect to each other, giving rise to various fascinating behaviors. In a recent research, the team showed that by inducing a phenomenon known as spin-orbit coupling, magic-angle graphene becomes a powerful ferromagnet.

"Magnetism and superconductivity are usually at opposite ends of the spectrum in condensed matter physics, and it's rare for them to appear in the same material platform," said Jia Li, an assistant professor of physics at Brown and senior author of the research. "Yet we've shown that we can create magnetism in a system that originally hosts superconductivity. This gives us a new way to study the interplay between superconductivity and magnetism, and provides exciting new possibilities for quantum science research."

Read the full story Posted: Jan 09,2022

Researchers succeed in measuring the properties of spin waves in graphene

Researchers from Harvard University and Japan's National Institute for Materials Science have demonstrated a new way to measure the properties of spin waves in graphene.

New method to measure spin waves in graphene imageA charge sensor measuring the cost of electrons surfing on the spin wave (green wavy lines) (Credit: Yacoby Lab/ Harvard SEAS)

Spin waves, a change in electron spin that propagates through a material, could fundamentally change how devices store and carry information. These waves, also known as magnons, don’t scatter or couple with other particles. Under the right conditions, they can even act like a superfluid, moving through a material with zero energy loss.

Read the full story Posted: Dec 15,2021

Researchers use graphene and other 2D materials to create a spin field-effect transistor at room temperature

Researchers at CIC nanoGUNE BRTA in Spain and University of Regensburg in Germany have recently demonstrated spin precession at room temperature in the absence of a magnetic field in bilayer graphene. In their paper, the team used 2D materials to realize a spin field-effect transistor.

Sketch of a graphene-WSe2 spin field-effect transistor imageSketch of the spin field-effect transistor. Image from article

Coherently manipulating electron spins at room temperature using electrical current is a major goal in spintronics research. This is particularly valuable as it would enable the development of numerous devices, including spin field-effect transistors. In experiments using conventional materials, engineers and physicists have so far only observed coherent spin precession in the ballistic regime and at very low temperatures. Two-dimensional (2D materials), however, have unique characteristics that could provide new control knobs to manipulate spin procession.

Read the full story Posted: Sep 08,2021

“Bite” defects revealed in graphene nanoribbons

Two recent studies by a collaborative team of scientists from two NCCR MARVEL labs have identified a new type of defect as the most common source of disorder in on-surface synthesized graphene nanoribbons (GNRs).

Combining scanning probe microscopy with first-principles calculations allowed the researchers to identify the atomic structure of these so-called "bite" defects and to investigate their effect on quantum electronic transport in two different types of graphene nanoribbon. They also established guidelines for minimizing the detrimental impact of these defects on electronic transport and proposed defective zigzag-edged nanoribbons as suitable platforms for certain applications in spintronics.

Read the full story Posted: May 26,2021

Magnetic graphene could boost generation of spin currents

A team of researchers from The University of Groningen and Columbia University have found that 2D spin-logic devices could benefit from magnetic graphene that can efficiently convert charge to spin current, and can transfer this spin-polarization over long distances.

Graphene is known amongst 2D materials for transporting spin information, but cannot generate spin current unless its properties are modified – conventionally cobalt ferromagnetic electrodes are used for injecting and detecting the spin signal.

Read the full story Posted: May 09,2021